Under the Clean Water Act, stormwater is considered a nonpoint source. Accordingly, benchmark standards and best management practices have been used to manage stormwater discharges. At least in California, that all changes on July 1, 2020, as amendments to California’s Statewide General Permit for Storm Water Discharges Associated with Industrial Activities (“Industrial General Permit” or IGP) go into effect. The amendments include effluent limits for a variety of substances based on Total Maximum Daily Loads (TMDLs) adopted for impaired waterways – ranging from copper and other metals to nitrogen and phosphorus to fecal coliform and even trash for certain waterways.

In recognition of the difficulties associated with meeting effluent limits for stormwater discharges, the amended IGP provides compliance options with significant incentives for stormwater capture and infiltration. In addition, the amended IGP supports requests for additional time to meet the new standards. New options and incentives that will be available for dischargers under the amended IGP include:

• New On-Site Compliance options that allow dischargers to meet a standard for stormwater capture and/or diversion and to be “deemed in compliance” with many IGP requirements.
• New Off-Site Compliance incentives that support partnerships between dischargers, local governments and organizations to develop watershed-based stormwater projects.
• Expanded consideration of Time Schedule Orders (TSOs) that can allow additional time to implement Best Management Practices (BMPs) to meet new requirements.

The amended IGP also includes more rigorous discharge testing standards, based on the federal Sufficiently Sensitive Methods Rule.

For more information on the California IGP or other stormwater compliance issues, contact Angela Levin, angela.levin@troutman.com, Andrea Wortzel, andrea.wortzel@troutman.com, or Louise Dyble, louise.dyble@troutman.com.